1. Field of Invention
The present invention relates to a bumper rail for a vehicle. More particularly, the present invention relates to a bumper rail for a vehicle, which is assembled into the front bumper of the vehicle to increase stiffness.
2. Background Art
Generally, vehicle bumpers are installed both at the front and rear ends of the vehicle to protect a vehicle body, and absorb an impact to protect occupants at the time of vehicle collision.
Bumpers disposed at the front side of the vehicle body have a structure in which a bumper cover, an impact-absorbing foam, and a bumper rail are sequentially arranged, and perform a function of mitigating impact energy from the front impact of vehicles.
For example, the bumpers of vehicles are disposed at the front side of the vehicle body include a bumper cover having a C-shaped section and formed of a plastic material, an impact-absorbing foam disposed at the inner side of the bumper cover to absorb impact energy, and a bumper rail disposed at the rear side of the impact-absorbing foam.
Particularly, the bumper rail serves to absorb most impact energy from the front side of vehicles while having a rectangular shape of closed section.
The bumper rails are usually manufactured by roll-forming hot rolled steel sheets.
FIGS. 1A and 1B are a perspective view and a cross-sectional view, respectively, illustrating a typical bumper rail of a vehicle.
As shown in FIGS. 1A and 1B, a bumper rail 10 is formed of a panel member having a C-shaped section, and is coupled with a reinforcing member 11 at the rear side thereof to form a closed section together with the reinforcing member 11.
Recently, the section of the bumper rail is being reinforced with an SPTD 1,470 class pipe 12 to enhance its stiffness in preparation for low-speed crash and offset crash of a vehicle.
The bumper rail 10 and the pipe 12 are CO2-welded, and then the reinforcing member 11 is spot-welded to from a bumper rail in which the pipe 12 and the reinforcing member 11 are integrally formed.
Here, a method of reinforcing a bumper rail with a pipe is more advantageous in terms of effect and weight than a method of increasing the thickness of the bumper rail and the reinforcing member.
However, a typical bumper rail structure has the following limitations.
First, since the bumper rail has a structure that is welded with an additional pipe, it is disadvantageous in terms of weight and incurs a cost increase.
Second, since the bumper rail and the pipe have to be CO2-welded at about 20 points, the cost increases, and a separate assembly jig is needed.
On the other hand, as examples of methods of enhancing the stiffness of a bumper rail in preparation for the low-speed crash and the offset crash, Korean Patent Application Publication Nos. 2011-122597 and 2010-131817 and Japanese Patent Application Publication Nos. 2002-264740 and 1999-91466 disclose methods of enhancing the stiffness by modifying the sectional shape of the bumper rail.
However, these methods have limitations in that the structure is complicated and the size is disadvantageous in terms of space utilization. Also, when considering the combination relation with peripheral components, since the whole layout needs to be changed, the efficiency is reduced in terms of actual application.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.